Our customer has a standard out of the box Small Business Server 2011 and uses Fusemail e-mail filtering services, between the mail server that is SBS 2011 and the recipients (the Internet). Fusemail will scan and filter e-mail both inbound and outbound.
In the Fusemail configuration there is a PUBLIC LEG and a PRIVATE LEG to configure TLS Encryption for e-mail if required. So we have enabled the PUBLIC LEG and set up a destination DOMAIN so that e-mails between our customer and this 3rd party would always be TLS Encrypted - Enforced. In actual fact the PUBLIC LEG only enforces TLS encryption between FUSEMAIL (for the customer) and the 3rd party e-mail DOMAIN.
The PRIVATE LEF will only TLS Encrypt e-mail between FUSEMAIL and the customer mail server, this completing the journey between the customer and this 3rd party. That should all work, however while the PUBLIC LEG is testing as being O.K., the PRIVATE LEG is NOT!
Every time we enable the PRIVATE LEG on the FUSEMAIL configuration, the inbound mail does not get delivered and just queues up at Fusemail. When we disable it again, the inbound mail flows as normal, but not encrypted. Fusemal report that our SBS 2001 is not sending out the STARTTLS command, however we think it is.
In SBS 2011 we have Exchange 2010, and we have ticked
the box in the EMC for Enable Domain Security (Mutual Auth TLS) - see attached. We also have a secure certificate for the customer domain and it is enabled for SMTP.
When we do our test :- telnet mail.domainname.com 25 followed by ehlo we do see a 250 STARTTLS in the listing.
Can someone advise what we might be doing wrong here.